Select your product to confirm this information applies to you
FAA Data Comm Quick Start Information
FAA Data Comm for Garmin® avionics can be signed up through FltPlan.com
Enroute CPDLC can be filed in the US where it is operational.
If you have enrolled in the PDC program, a separate email will be sent to you with directions on how to setup your account for the email/text notifications, as well as how to read a PDC.
It is important to note, that there are requirements revolving around participation in the Data Comm program that are independent of Garmin.
Here are Some Highlights About the Program that you Should be Aware of
CPDLC DCL (Departure Clearance) support is not available at every airport in the US.
When you initiate a logon while at an airport that supports CPDLC DCLs, the ground system will analyze the data in your logon request (from the ATC Data Link Page) as well as your filed flight plan. A departure clearance will not be issued if the filed flight plan did not correlate with the information given on the logon, or if there were other issues with the filed flight plan.
There are filing codes for fields 10 and 18 in the ICAO flight plan. You cannot operate enroute CPDLC without filing these codes in your flight plan.
Not every ARTCC supports enroute CPDLC. Enroute CPDLC will only be offered if flying within the airspace of an ARTCC that supports enroute CPDLC.
All of this information and much more guidance can be found at l3harris.com/datacomm.